The Handbook of Behavioral Medicine

David I. Mostofsky

• Publisher: Wiley-Blackwell
• Year: 2014
• Print ISBN: 9781118453995
• eBook ISBN: 9781118453858
• Edition: 1
• Topic: Psicología
• Subtopic: Psicología fisiológica

Handbook of Behavioral Medicine presents a comprehensive overview of the current use of behavioral science techniques in the prevention, diagnosis, and treatment of various health related disorders.

• Features contributions from a variety of internationally recognized experts in behavioral medicine and related fields
• Includes authors from education, social work, and physical therapy
• Addresses foundational issues in behavioral medicine in Volume 1, including concepts, theories, treatments, doctor/patient relationships, common medical problems, behavioral technologies, assessment, and methodologies
• Focuses on medical interface in Volume 2, including issues relating to health disorders and specialties; social work, medical sociology, and psychosocial aspects; and topics relating to education and health

2 Volumes

Part I

Domains of Concepts, Theories, and Treatments

1

Depression in Chronic Physical Illness

A Behavioral Medicine Approach

Golan Shahar, Dana Lassri, and Patrick Luyten

In this chapter, we address the prevalence, consequences, and presumed causes of unipolar depression in chronic, non-lethal, physical illness. We begin by outlining the central role of chronic physical illness (CPI) in medicine. Next, we consider the various manifestations of depression in CPI, focusing on the distinction between categorical approaches to depression (i.e., a diagnosable condition such as major depressive episode) and dimensional approaches (i.e., elevated levels of depressive symptoms in the absence of a diagnosable episode) to depression. From a behavioral medicine point of view, we argue, it makes more sense to address depression as a continuous dimension rather than to distinguish between diagnosable and “subsyndromal” depression. Next, we present a tentative model accounting for depression in CPI, which focuses on person–context exchanges. We conclude by discussing the implications of this view for assessment/screening, treatment, and prevention.

Chronic Physical Illness: Definition, Prevalence, Costs

The World Health Organization (WHO) defines chronic diseases as diseases of long duration and generally slow progression. According to the US National Center for Health Statistics, a disease lasting 3 months or more is considered chronic (http://www.who.int/topics/chronic_diseases/en). Chronic diseases refer to a variety of medical and functional somatic conditions (i.e., cancer, chronic kidney disease, chronic obstructive pulmonary disease, chronic pelvic pain, chronic pain, chronic respiratory diseases, diabetes, epilepsy, fibromyalgia, headache, heart disease, rheumatoid arthritis, systemic lupus erythematosus, etc.) characterized by different levels of life-threatening conditions (terminal vs. non-terminal conditions), symptom severity and duration (constant, episodic flare-ups or exacerbations, or remission with an absence of symptoms for long periods of time), illness appearance (suddenly or through an insidious process), etc. As opposed to an acute disease, which is typically characterized by an abrupt onset of symptoms that terminates in a relatively short period, either with recovery or with death, chronic illness might continue endlessly, and often becomes a defining part of the individual's life experience.

Chronic illnesses constitute a growing proportion of the total global disease burden (Katon & Ciechanowski, 2002; Lopez, Mathers, Ezzati, Jamison, & Murray, 2006; Welch, Czerwinski, Ghimire, &Bertsimas, 2009). Over the last 50 years, chronic illnesses have steadily overtaken acute medical conditions as the primary cause of disability and use of health services in the United States. Studies show that 45% of the US population is afflicted with CPI, which accounts for 78% of health expenditure (Anderson & Horvath, 2004; Holman, 2004). Chronic illness is predicted to become ever more prevalent as populations age across developed countries and effective treatment is found for acute conditions. In fact, it is predicted that, by the year 2020, CPI will account for 60% of the global disease burden (Murray & Lopez, 1997; Welch et al., 2009).

A distinction between “disease” and “illness” is made in (behavioral) medicine in general, and particularly with respect to CPI. While the term disease pertains to the pathophysiology underlying the syndrome/symptoms, (e.g., an alteration in structure and function), the term illness pertains, more broadly, to the human experience of symptoms and suffering, and pertains to how a disease is perceived, lived with, and responded to by an individual and his family (Larsen & Lubkin, 2009, p. 4). Related to this distinction, Curtin and Lubkin (1995, pp. 6–7), define chronic illness as the irreversible presence, accumulation, or latency of disease states or impairments that involve the total human environment for supportive care and self-care, maintenance of function, and prevention of further disability.

In accord with the aforementioned definition, chronic illness may be considered a chronic stressor. As explained in more detail in the following text, stress may be defined as a threat (or perceived threat) to the organisms' allostasis or dynamic equilibrium (McEwen, 2007), caused by a physical and/or psychosocial burden (Van Houdenhove, Egle, & Luyten, 2005). Stress is thought to influence health both indirectly by promoting behavioral coping responses detrimental to health and by activating physiological systems (i.e., the sympathetic nervous system and directly by its effects on the hypothalamic–pituitary–adrenal (HPA) axis; Cohen, 2004; Lupien, McEwen, Gunnar, & Heim, 2009). Prolonged or repeated activation of these systems is thought to place persons at risk for the development of a range of physical and psychiatric disorders (Anda et al., 2006; Luyten, Van Houdenhove, Lemma, Target, & Fonagy, in press), and depression in particular (Monroe & Reid, 2009; Pae et al., 2008).

Prevalence of Depression in Chronic Physical Illness

It is therefore of no surprise that unipolar depression is highly prevalent in CPI. Depression ranks fourth for disability-adjusted life-years worldwide (Insel & Charney, 2003), and is estimated to rise to second by 2020 (Murray & Lopez, 1997). Every year, 6% of adults will suffer from depression, and more than 15% of the population will experience a depressive episode during their lifetime (Pilling, Anderson, Goldberg, Meader, & Taylor, 2009). Recently, the 1-year prevalence of a depressive episode among the chronically physically ill, based on ICD-10 criteria, has been shown to range between 9.3% and 23% and to be significantly higher than the likelihood of having depression in the absence of a CPI (Moussavi et al., 2007).

Extensive research has demonstrated the association between depression and high utilization of medical services, indicating significantly higher medical costs among patients with either depressive symptoms or major depression in comparison to non-depressed patients (Katon & Ciechanowski, 2002; Welch et al., 2009). This increase in costs is seen in a variety of categories, including primary care visits, medical specialty visits, lab tests, pharmacy costs, inpatient medical costs, and mental health visits. This was also found after adjusting for chronic medical illness. Additionally, depressed patients were found to have higher costs than non-depressed elderly (Katon & Ciechanowski, 2002).

Welch et al. (2009) have shown that depressed patients had higher non-mental-health costs than non-depressed patients in 11 comorbid illnesses studied, while the per-patient difference in non-mental-health cost between depressed and non-depressed patients ranged from US$1,570 in obesity to US$15,240 in congestive heart failure. The ratio of cost between non-depressed and depressed patients ranged from 1.5 in obesity to 2.9 in epilepsy. Depression was associated with significantly higher cost of non-mental healthcare in 10 of 11 chronic comorbid diseases studied. Even while controlling for number of chronic comorbid diseases, depressed patients had significantly higher costs than non-depressed patients. Though the magnitude of the cost difference was similar to that reported in previous studies, the consistency of the magnitude across 11 chronic comorbid diseases has not been previously reported. Also, the largest components of higher cost in depression were higher pharmaceutical and outpatient costs. Further research is necessary to determine the underlying reasons for these variations. However, these differences in utilization do indicate that depressed patients not only saw doctors more often, but also were prescribed non-mental-health drugs at higher cost or in greater quantity than non-depressed patients.

Though the increased cost of general medical services associated with depression has been established in several different medical settings, using cost of services as a measure of utilization of care, the cause of higher cost in depressed patients remains unclear. Thus, it is unclear whether these individuals suffer chronic comorbid illnesses of greater severity, or if they are seeking more medical care than non-depressed individuals, independently of illnesses severity, or whether they have poor compliance with medical care or even alterations in pathophysiology triggered by depression.

Depression: Categorical and Dimensional Approaches

However, what exactly is depression? For the last two and a half decades, depression researchers have been discussing whether depression is a binary, all-or-none, clinical entity such as the ones described in leading psychiatric diagnostic manuals such as the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR, published by the American Psychiatric Association, 2000) or the International Statistical Classification of Diseases and Related Health Problems–10 (ICD-10; World Health Organization, 2008), as opposed to a continuous variable denoting various levels of severity that might be ordered along a known and measurable continuum, such as scores on the Center for Epidemiological Studies Depression Scale (CESD; Radloff, 1977). Two scientific approaches were taken in order to resolve the debate: employment of new taxometric procedures to examine the extent to which depression is a continuum or a taxon on the one hand and the systematic examination of impairment associated with “subsyndromal depression” on the other, namely, whether elevated levels of depressive symptoms, in the absence of a formal DSM/ICD diagnosis, are associated with impairment. Evidence pertaining to both approaches is briefly reviewed.

Developed by Waller and Meehl (1998), taxometics is a statistical procedure aimed at identifying categories from dimensions, so as to establish the optimal indicators and base rates of the putative category (taxon). Simply put, taxometrics purports to provide an answer to the question “is a certain variable (e.g., depression) binary or continuous?” The idea behind taxometrics is that valid indicators of a potential taxon intercorrelate in which taxon members and non-members are mixed, but do not correlate in “pure” samples. Thus, the size of the correlation between key indicators of depression (e.g., self-report measures such as the CESD or the Beck depression inventory–II [BDI-II]; Beck, Steer, & Brown, 1996), computed for samples comprised of either depressed, non-depressed, and mixed individuals, should indicate the existence – or not – of a depression taxon. The problem, however, is that there are few studies that rely on this sophisticated procedure in depression research, and, thus far, results have been mixed, some consistent with the presence of a depressive taxon while some are not (e.g., Beach & Amir, 2003, Franklin, Strong, & Greene, 2002; Grove et al., 1987; Hankin, Fraley, Lahey, & Waldman, 2005; Ruscio & Ruscio, 2000; Whisman & Pinto, 1997; for a review, see Pettit & Joiner, 2006, p. 15).

Another approach is to examine whether elevated levels of depressive symptoms, assessed as a continuous variable, are associated with psychosocial and medical impairment, regardless of the presence or absence of a depressive taxon. This approach might be extended by comparing individuals with a formal diagnosis of major depressive disorder (MDD), with those who do not meet criteria for such a diagnosis, but who have elevated scores on a depression measure. Here, the pattern is clear: elevated scores of depressive symptoms on the CESD, BDI-II, or other measures are associated with substantial psychosocial impairment, which is sometimes equivalent to the impairment experienced by people with MDD (e.g., Judd, Akiskal, & Paulus, 1997).

Taking into consideration the two lines of evidence, we conclude that, for practical purposes, unipolar depression in chronic illness should be considered as serious even when it is subsyndromal, namely, when patients reported elevated levels of depression on a self-report measure, but do not meet criteria for an MDD diagnosis. Accordingly, henceforth, we use the term “depression” in its wider use, denoting elevated levels of depressive symptoms.

Role of Depression in CPI

Various models of the relationship between depression and CPI have been proposed, and evidence seems to support in part each of these approaches.

First, CPI might lead to depression. For instance, in a prospective study of non-depressed elderly living in the community, the most common stressful life event that was associated with the onset of major depression was the development of a life-threatening medical illness in the respondent or his/her spouse (Wells, Golding, & Burnham, 1988). Studies addressing the onset of depression as a secondary consequence of the existenc...

Table of contents

• Cover
• Series page
• Title page
• Copyright page
• Contributors
• Foreword
• Preface
• Volume 1: Foundational Issues
• Volume 2: Medical Interface
• Index of Authors
• Index of Subjects